I visited the tire specialist today. All four tires had balance issues between 5 and 20 grams. Even though the tires were balanced and road forced balanced about three week ago.
Additionally, three out of four tires showed whobbles in the shoulder (side wall). (the side of the tire is not completely flat. Only one tire 'looked like a new tire would', according to the specialist.
They rebalanced all wheels and moved the best tire to the front right position. However, the steering wheel still shakes. They think the whobbles in the tires can be the source.
I then went back to BMW and showed the results. They now escalate to BMW NL and have their tech look at my car. The chief mechanic drove with me and is convinced this is abnormal behaviour for van 320, especially when the steering rack has been replaced.
We agreed they will not return my car as long as they issue is there, even if this means they have to reorder a new one.
I made a video of the shaking. It is quite hard to see, but in the second part i press the phone to the wheel. You can see the shaking. Please not that the car drives over a ridge in the road. This is not visible in the wheel. The suspension seems oke.
The second vid shows the whobbles.
Please look at the spots on the floor for reference